Abstract
Fusobacterium nucleatum is a gram-negative anaerobic bacterium commonly associated with periodontal disease. However, its role in extraoral infections, particularly in immunocompetent individuals, is increasingly recognized. We report a rare case of hepatorenal abscess caused by F. nucleatum in a previously healthy woman, initially suspected to have a malignant tumor based on PET-CT findings. Next-generation sequencing (NGS) of abscess aspirate confirmed the pathogen. The patient responded well to targeted antibiotic therapy. This case highlights the importance of considering anaerobic pathogens in deep-seated abscesses and the utility of NGS in achieving accurate microbial diagnosis.